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Biomedical subjects

L Rogers

Publications and source records attributed to L Rogers.

At least 19 recordsLinked to original sources
PubMed1995

The accuracy of video imaging in orthognathic surgery.

Video imaging is an important emerging technology in planning orthognathic surgery and educating patients about the esthetic effects of treatment. The presurgical cephalograms of 56 patients, 41 with mandibular advancement alone and 15 with mandibular advancement plus genioplasty, were digitized, and the computer-generated soft tissue "line drawing" predictions were compared with the actual posttreatment cephalograms. Video images of the patients' presurgical lateral view were obtained, and two experienced clinicians compared the computer generated video image predictions with the actual posttreatment profile. Video images judged very good or excellent were considered acceptable for treatment planning; 60% to 83% met this criterion, depending on the profile area viewed. The percentage of acceptable images in the lower lip, labiomental fold, and chin area decreased with the addition of a genioplasty. The predicted and actual posttreatment soft tissue line drawings were quite similar for all areas except for the lower lip region, where statistically significant differences were noted, with the predicted lower lip more retrusive and thinner than the actual contours. For the lower lip and chin, a 2 mm or more discrepancy was observed in 20% of the patients. In all cases, the actual image was judged more esthetic than the predicted image, allaying fears of unrealistically optimistic computer generated predictions.

Adult↗
PubMed1995

Leptomeningeal dissemination of malignant glioma simulating cerebral vasculitis. Case report with angiographic and pathological studies.

BACKGROUND: The complex clinical and radiological picture of leptomeningeal spread of tumor is well recognized as a problem of systemic cancer but is less frequent in primary cerebral glioma, particularly as a presenting picture. While brain ischemia and infarction may occur in patients with subarachnoid tumor, the mechanism for these complications remains unclear. Angiographic and pathological demonstrations of direct vascular involvement by disseminated glioma are particularly sparse. We report a patient presenting with multiple infarctlike lesions with postmortem evidence of direct vascular involvement by glioma. CASE DESCRIPTION: A 54-year-old woman presenting with seizures, headache, and changes in mental status was found to have vascular narrowing in cerebral blood vessels and ischemic lesions on neuroimaging studies of the brain, interpreted as cerebral vasculitis. A brain biopsy showed leptomeningeal glioma. Postmortem examination demonstrated a glioblastoma arising around the right sylvian fissure with extensive subarachnoid dissemination of tumor. The leptomeningeal tumor caused vascular narrowing by encasement, direct vascular wall invasion, and thrombosis and was associated with underlying infarctlike foci of parenchymal necrosis. CONCLUSIONS: This case demonstrates an unusual presentation of glioblastoma clinically and radiographically mimicking cerebral vasculitis, and it illustrates a variety of mechanisms for tumor-produced vascular compromise.

Cerebral Angiography↗
PubMed1995

Mortality in a migrating Mennonite church congregation.

Preston's two-census method of demographic estimation is applied to three pairs of reconstructed censuses from the records of a migrating Mennonite church congregation covering the period 1780-1890. The three pairs of censuses correspond to three periods (1780-1790, 1850-1860, and 1880-1890) and to stays in three settings (Prussia, Russia, and Kansas, respectively). The Mennonites' stay in Prussia was a period of hardship. In Russia they expanded their economic base and developed new farming methods, dramatically increasing their productivity. The Mennonites took these skills to Kansas, where they continued to be successful. The increase in life expectancy at age 5 corroborates this picture. The Prussian period exhibits the shortest life expectancy for both sexes. After the move to Russia, life expectancy increased for both sexes and continued to increase with the move to Kansas. The model also provides limited evidence for fertility depression following the move to Kansas.

Adolescent↗
PubMed1993

Hyperplastic polyps: a cell lineage which both synthesizes and secretes trefoil-peptides and has phenotypic similarity with the ulcer-associated cell lineage.

Hyperplastic polyps are common benign lesions of uncertain histogenesis, which occur in the colon in populations at risk for colorectal carcinoma. They contain neutral/MUC1 gene-related mucin which in turn is closely associated with the trefoil-peptide pS2, a major component of the ulcer-associated cell lineage, previously termed pseudopyloric metaplasia. We have examined 17 hyperplastic polyps for expression of the trefoil-peptides pS2 and human spasmolytic polypeptide by in situ hybridization and immunohistochemistry, as well as by using antisera to epidermal growth factor/urogastrone and its receptor and to epitopes of the product of the MUC1 gene to characterize any further similarity between these lesions and the ulcer-associated cell lineage and thus help elucidate the nature of the lesions. Our investigations show both human spasmolytic polypeptide and pS2 messenger RNA within the polyps, whereas only pS2 peptide could be demonstrated immunohistochemically. Epidermal growth factor/urogastrone, its receptor, and antisera to the MUC1 gene also showed widespread staining of these polyps. We suggest that hyperplastic polyps are formed of a lineage that both synthesizes and secretes trefoil-peptides and the MUC1 mucin and that hyperplastic polyps may be related to the phenotypically similar ulceration-associated cell lineage.

Cell Line↗
PubMed1992

Differential expression of clusterin in inducible models of apoptosis.

Apoptosis (programmed cell death) and necrosis can be readily distinguished morphologically and biochemically. The most striking biochemical change observed in apoptotic cells is the cleavage of the genomic DNA into discrete nucleosome sized fragments, producing a laddering pattern when the DNA is examined electrophoretically. It has recently been shown that RNA and protein products of the testosterone-repressed prostate message-2 gene are induced, coordinate with the onset of cell death. This gene has been isolated from a variety of species and tissues, it is highly conserved, and collectively referred to as clusterin. We have examined a number of inducible leucocyte models of apoptosis, including glucocorticoid and calcium ionophore induced thymocyte death, 'aged' neutrophils and cytotoxic T cells, and found that in these situations that cell death is not associated with up-regulation of clusterin gene expression. The finding that clusterin is not expressed in all cells undergoing apoptosis would suggest that this molecule is not critical to the mechanism of cell death. It does, however, provide the first example of a readily detectable marker which is differentially expressed in cells undergoing apoptosis and adds further weight to the argument that apoptosis is not a uniform phenomena, but is dependent on the nature of the cells involved and the means of induction.

Animals↗
PubMed1992

Stromal expression of 72 kda type IV collagenase (MMP-2) and TIMP-2 mRNAs in colorectal neoplasia.

We undertook an in situ hybridization study to localize the mRNAs for the 72 kda type IV collagenase (MMP-2) and its specific inhibitor (TIMP-2) in 12 colorectal carcinomas, 3 adenomas, and 4 uninvolved resection margins to see how their distributions correlated with that of the reported distribution of MMP-2 protein. Labeling for MMP-2 and TIMP-2 mRNAs was detectable in 10 of 12 carcinomas and in 2 of 3 adenomas. Unexpectedly, we found much stronger signals for MMP-2 and TIMP-2 mRNAs within the mesenchymal cells in the desmoplastic stroma, of endothelial and/or (myo)fibroblastic nature, rather than in tumor epithelial cells in which localization of MMP-2 was anticipated. Our data indicate that stromal cells may have the ability to synthesize a metalloproteinase that degrades basement membrane, and may together with the neoplastic epithelial cells participate actively in the tissue remodeling and disruption of the basement membrane integrity which is characteristic of invasive tumors.

Actins↗
PubMed1991

Estradiol induces proliferation of peroxisome-like microbodies and the production of 3-hydroxy fatty acid diesters, the female pheromones, in the uropygial glands of male and female mallards.

During the mating season the female mallards produce sex pheromones, diesters of 3-hydroxy fatty acids, in their uropygial glands. Subcellular fractionation by sucrose and Nycodenz density gradient centrifugations and electron microscopic examination of the fractions showed that diesters of 3-hydroxy acids and the enzymes that catalyze the formation and esterification of the 3-hydroxy fatty acids are located in the catalase-containing fractions, probably peroxisomes, whereas monoester synthesizing activities are located in the endoplasmic reticulum. Fatty acyl-CoA reductase that would provide fatty alcohol needed for the synthesis of monoester and diester waxes was found both in the peroxisomal and endoplasmic reticulum fraction. Upon daily intramuscular injection of estradiol into the females in the nonmating season, the short chain monoester waxes of the uropygial glands were replaced by long chain monoester waxes, and subsequently the monoester waxes were replaced by diester waxes. Injection of thyroxine with estradiol hastened the induction of the compositional changes including diester synthesis. Similar changes, including the synthesis of the female pheromones, were induced in the uropygial glands by the hormone treatment of males that do not normally produce diesters at any time during their life cycle. The structure and composition of the diesters induced by hormone treatment of both males and females were identical to those of the female pheromones produced during their mating season. Electron microscopic examination of diaminobenzidine-treated glands showed that peroxisomes proliferated in the gland of the females in the mating season and in the estradiol-treated males that produce the diesters.

Animals↗
PubMed1991

Developmental changes in the expression of S-acyl fatty acid synthase thioesterase gene and lipid composition in the uropygial gland of mallard ducks (Anas platyrhynchos).

Developmental changes in the composition of the uropygial gland secretory lipids of the postembryonic mallard ducks (Anas platyrhynchos) were determined. During the first 3 weeks after hatching, the composition of the secretory lipids remained constant; the lipids consisted of long-chain wax esters composed of a complex mixture of n-, monomethyl, and dimethyl fatty acids esterified to n-C16 and n-C18 fatty alcohols. Afterward, as the ducks began to acquire adult feathers, short-chain wax esters composed of 2- and 4-monomethyl fatty acids began to appear with 2-methylhexanoyl and 4-methylhexanoyl as the major acyl components; esters of short-chain monomethyl fatty acids (less than or equal to C12) constituted 90% of the lipids when the ducks were 2 months old and had acquired adult plumage. The appearance of the short-chain acids in the acyl portion of the wax esters was accompanied by the appearance of S-acyl fatty acid synthase thioesterase, which can hydrolytically release short-chain acids from fatty acid synthase in the gland. Northern blot analysis showed that the gland-specific thioesterase gene transcripts began to appear in the gland only 3 weeks after hatching. The appearance of the transcripts and immunologically detectable thioesterase protein reached maximum levels 2 months after hatching, with the acquisition of the adult plumage. Thus, the developmental changes in lipid composition correlated with the changes in the level of expression of the thioesterase gene. Expression of other gland-specific genes has been previously found to begin just prior to hatching. The gland-specific thioesterase is the first case of delayed expression of a gland-specific gene.

Animals↗
PubMed1988

Experience with younger siblings facilitates maternal responsiveness in pubertal Norway rats.

The latency of maternal behavior (MB) onset induced by cohabitation with pups (sensitization) increases in female and male Long-Evans rats from 24 days of age (1-2 day latency) to 42 days of age (4-5 day latency). This decline in maternal responsiveness at Day 42 did not occur in 50% of rats ("responders") which lived with their dam and younger siblings (conceived during the postpartum estrus) for either 4 or 11-18 days after their birth. In contrast to cessation of suckling at about Day 25 postpartum in the absence of a 2nd litter, when a 2nd litter was born greater than Day 26 or less than Day 26 postpartum, suckling continued for a mean of 32 and 35.5 days, respectively (and up to Day 40). Also, time spent suckling during the 10 days following the birth of the 2nd litter was more than five times as great if the 2nd litter was born with little or no delay (less than Day 26). The offspring from the 1st litter spent about 80% of the diurnal observation time in proximity to the dam and younger siblings, and instances of nurturance (retrieving, crouching, licking) toward the young littermates were observed. However, the only dam-litter interaction significantly related to subsequent maternal responsiveness by 1st litter offspring was a positive relation between the prior incidence of aggression by mothers towards juveniles and sensitization latency.

Animals↗
PubMed1988

Medulloblastoma in association with the Coffin-Siris syndrome.

An 8-year old patient with Coffin-Siris syndrome is presented, who was found to have a medulloblastoma during the evaluation of apnea and ventilator dependency. Although several cases of Dandy Walker cysts and one case of brain-stem heterotopia have been described in this rare syndrome, this is the first report of medulloblastoma in a patient with Coffin-Siris syndrome. Possible pathogenetic mechanisms are briefly discussed.

Abnormalities, Multiple↗
PubMed1988

Infection of Peruvian Aotus nancymai monkeys with different strains of Plasmodium falciparum, P. vivax, and P. malariae.

Aotus nancymai (karyotype I) monkeys from Peru were studied for their susceptibility to infection with Plasmodium falciparum, P. vivax, and P. malariae. Three strains of P. falciparum (Santa Lucia from El Salvador, Indochina I/CDC from Thailand, and Uganda Palo Alto) were inoculated into 38 monkeys. The results indicated that this species of Aotus monkey is highly susceptible to infection. The Uganda Palo Alto and the Santa Lucia strain parasites appear to be the most useful for immunologic and chemotherapeutic studies. Five strains of P. vivax (Chesson, ONG, Vietnam Palo Alto, Salvador I, and Honduran I/CDC) were inoculated into 28 monkeys. The Vietnam Palo Alto strain produced the highest level parasitemias ranging from 23,800 to 157,000/mm3. Mosquito infections were obtained with the ONG, Chesson, and Salvador I strains. Two out of 6 attempts to transmit P. vivax via sporozoite inoculation to splenectomized monkeys were successful with prepatent periods of 39 and 57 days. Five monkeys were infected with the Uganda I/CDC strain of P. malariae. Maximum parasitemias ranged from 10 to 5,390/mm3.

Animals↗
PubMed1987

Acute arsenic intoxication presenting as Guillain-Barré-like syndrome.

Arsenic-induced polyneuropathy is traditionally classified as an axonal-loss type, electrodiagnostically resulting in low amplitude or absent sensory and motor responses, relatively preserved proximal and distal motor conduction rates, and distal denervation. We report four patients with a subacute onset progressive polyradiculoneuropathy following high-dose arsenic poisoning. In three patients, early electrodiagnostic testing demonstrated findings suggestive of an acquired segmental demyelinating polyradiculoneuropathy. Serial testing confirmed evolution into features of a distal dying-back neuropathy. We hypothesize that arsenic toxicity and the resultant biochemical derangement of the peripheral nerve cell leads to subtle changes in axonal function that produce, initially, segmental demyelination and eventually distal axonal degeneration. Acute arsenic toxicity must be suspected in patients with clinical and electrodiagnostic features supporting Guillain-Barré syndrome.

Action Potentials↗
PubMed1987

Biosynthesis of 3-hydroxy fatty acids, the pheromone components of female mallard ducks, by cell-free preparations from the uropygial gland.

Diesters of 3-hydroxy C8, C10, and C12 acids, the female mallard duck pheromones, were found as the major products of the uropygial glands only during the breeding season. The 3-hydroxy acids were identified by mass spectrometry of the trimethylsilyl ethers of the methyl esters and of the diols derived from LiAlH4 reduction of the hydroxy acids. A cell-free extract from the gland catalyzed conversion of dodecanoic acid to 3-hydroxydodecanoic acid which was identified by radio thin-layer and radio gas chromatographic analysis of the enzymic products as methyl-3-acetoxydodecanoate and as diacetate of the diol generated by LiAlH4 reduction of the enzymic product. The enzymic introduction of the hydroxyl group at C-3 was catalyzed mainly by a 50,000g pellet prepared from a 1000g supernatant obtained from the cell-free extract. This reaction required ATP, CoA, and O2, and the CoA ester of the acid was more efficiently converted than the free acid to the 3-hydroxy acid. KCN at 1 mM and 50% CO did not inhibit the reaction. 3H from 3H2O was incorporated into 3-hydroxydodecanoic acid during the enzymic synthesis of this acid from dodecanoic acid. Mass spectrometry of the 3-hydroxy acid generated by the particulate fraction in the presence of H2 18O showed that 18O was incorporated as expected from hydration of a delta 2 double bond. From the above results it is tentatively concluded that peroxisomal acyl-CoA oxidase converts the acyl-CoA to the 2-enoyl-CoA which is hydrated to generate the 3-hydroxy acid.

Adenosine Triphosphate↗
PubMed1987

Diesters of 3-hydroxy fatty acids produced by the uropygial glands of female mallards uniquely during the mating season.

The uropygial gland secretions produced by female mallards (Anas platyrhynchos) throughout the year were analyzed by thin-layer chromatography and combined gas-liquid chromatography and mass spectrometry. Most of the year, the secretion was composed of wax esters. With the beginning of the mating season in the middle of March, a polar component appeared which became the dominant and sole component of the secretion through April and May and as the mating season ended in June, wax esters became the sole component of the secretion. The polar components were identified to be diesters of n-C8, n-C10, and n-C12 3-hydroxy acids with n-C16 and n-C18 alcohols and n-C6 to C16 even chain acids. Immediately after the diester-producing period the female uropygial glands produced very long chain wax esters composed of fatty acids longer than C12. By the end of August, shorter chain wax esters composed of C6 and C12 acids became the dominant components of the secretion and this composition, previously considered characteristic of mallards, remained constant until March. The observed disappearance of the short chain waxes during the postnuptial period is similar to that in males. The dramatic changes in the composition of the uropygial glands similar to those observed in the female mallards during the mating season have not yet been observed in any other species.

Alcohols↗
PubMed1986

Men, women, and religion: stress within leadership roles.

Stress in religious leaders was investigated by administering to 250 priests, ministers, seminarians, nuns, and brothers the specially devised Religion and Stress Questionnaire and the Osipow and Spokane Occupational Environment Scales, Personal Strain Questionnaire, and Personal Resources Questionnaire. In-depth interviews were also conducted with 10% of the subjects. Religious leaders experienced lower overall occupational stress and personal strain and evidenced more personal resources than did the normative population. ANOVAs showed ministers to have the highest overall occupational environment stress and vocational strain and next to the lowest scores in overall personal resources of the five groups of religious professionals. In terms of sensitivity to the stress that women in seminary and ministry experience, male and female seminarians and ministers were most aware of these issues, with priests (males only), nuns, and then brothers (in descending order) sensitive to these concerns.

Adaptation, Psychological↗
PubMed1986

Leptomeningeal metastasis from supratentorial malignant gliomas.

The clinical and diagnostic findings in 13 patients with leptomeningeal metastasis from supratentorial malignant gliomas are reported. Criteria for inclusion in this study were positive myelographic examination, positive cerebrospinal fluid cytology on two or more samples, or evidence of leptomeningeal seeding at autopsy. Eight patients had premortem symptoms of leptomeningeal metastasis, with the diagnosis confirmed during life in 5 patients. Average survival after the onset of symptoms was 3 months (range, 1 to 5 months). Comparison of the autopsied group with 10 concurrent autopsied patients without leptomeningeal gliomatosis did not reveal any significant differences in age, but leptomeningeal gliomatosis was more prevalent in patients with longer postoperative survival. Leptomeningeal involvement at autopsy was more extensive in symptomatic patients. Cerebrospinal fluid examination often gave nondiagnostic or nonspecific results. Computed tomography of the brain showed evidence of ventriculomegaly, periventricular contrast enhancement, or multifocal tumor involvement in every case. Iophendylate myelography was the most reliable diagnostic tool and established the diagnosis whenever performed. The natural history and clinical significance of leptomeningeal metastasis from supratentorial malignant gliomas are discussed.

Adolescent↗